Gas cutting apparatus



May 26, 1942. I J. D. McKlERNA 3 2,284,005

I eas cu'rrma APPARATUS w Filed m9 1, 1940 Patented a 26, 1e42- GAS CUTTING APPARATUS James D. McKicrnan, Brooklyn, N. Y., assignor to Air Reduction Company, Incorporated, New

UNITED ,S TAT E York, N. Y., a corporation of New York Application May 1, 1940, Serial No. 332,654

8 Claims.

This invention relates to gas cutting apparatus and especially to the control of the operation of one or more cutting torches of such apparatus. The invention can be used-with welding torches,

but its advantages are more fully realized in the cutting art where gas control requirements are more diflicult.

With oxygen cutting torches of thethree-hose type there are three separate gas supply lines on the lines 33 and 4--4, respectively, of Fig. 2.

A movable base or carriage l has four flanged wheels II that run on the edges of a pattern table l2. Two jointed arms l4 and I5 are supported by parallel posts extending upward from the carriage ill. The rearward links are held parallel to one another by a chain and sprocket connection within the carriage body, but can be held parallel by a connecting link or any of the other expedients that have been used for maintaining the rearward links parallel in machines of the folding parallelogram type.

The forward links of,the" jointed arms l5 are connected by a front bar l6 that is fastened that must be controlled by valves, and if the 10 to the forward ends of jointed arms by pivot' torch has a pilot light there is a fourth gas connections. The front bar lli is parallel'to the supply that may be valve controlled. With unlpattern table and has universal movement in a versal cutting machines, and especially those of plane. All positions of the front bar are parallel the folding parallelogram type which have the with one another so that a device connected'with torch and follower device longitudinally spaced. the front bar at any point. will move along the valve control mechanism accessible to an atsame path as a device attached to some other tendant standing near the torch may be inacpart of the front bar." r cessible to the attendant when he is operating A tracer I9 is held in a bracket attached to ,a tracer or other follower device. the front bar IS. The tracer 19 has a limited It is an object of this invention to provide 20 vertical'niovement in the bracket 20 and has a improved cutting apparatus which has more -contraction wheel 2| that rests on the pattern table venient and more effective control of the gas I2. The traction wheel 2| is driven by a motor supply to the torch or torches. Another object 22, and the tracer can be turned about a vertical of the invention is to provide improved means axis to cause the tracer wheel to follow the outfor controlling a number of different gas supply :5 line of a drawing or pattern in any and changvalves ina predetermined sequence which makes ing directions. The tracer 19, which is merely the cutting apparatus eflicient and avoids flashrepresentative of follower devices for guiding a backs when lighting the preheating flames. cutting machine in accordance with a predeter- A more particular object of the invention is, minedoutline, operates over the pattern table to provide improved gas control means for a-JO I2 which covers the area between the paths foluniversal cutting machine of the folding parlowed by the carriage wheels ll. allelogram type. In accordance with one feature An extension atone end of the front bar of the invention the gas control valves are lol6 supports one, or more torch holders 26, there cated on the frame of the machine and operated being two shown in the drawing, and these torch by cams on a shaft, the opposite ends of which :55 holders are rigidly secured to the extension 25 of are accessible from opposite sides of the machine the front bar so that they move along courses so that an attendant standing near either the similar to that followed by the'tracer. There is torch or tracer can conveniently control the gas a cutting torch 21 in each of the torch holders supply. 26 and these torches move over a field outside Other objects, features and advantages of the of the pattern table l2 while the tracer l9 folinvention will appear or be pointed out as the lows the outline of a pattern or drawing on the specification proceeds. table. 1

In the accompanying drawing, forming a part 7 Each of 1 the torches has tubing 28 forsupplyhereof: ing oxygen for a cutting jet, and there is separate Fig. lisa perspective view, partly broken away, tubing 29 and 30 for supplying fuel gas and showing a universal cutting machine embodying oxygen, respectively, for preheating flames. the invention. Each torch is equipped with a pilot 3 I and the Fig. 2 is an enlarged front elevation of the gas for this pilot flame is supplied through tubing valves and valve-operating means shown in Fig. 1. 32. I

' Figs.3 and4 are enlarged sectional views taken The tubing 28, 29, 30 and 32 connect with valves 34, 35, 36 and 31, respectively. These valves are located on the front bar 1 6. The ends of the tubing 28, 29, 30 and 32 connected with the valves are shown in Fig. l, but in the drawing only the tubing 32 is shown in full, the other tubing being broken away close to the valves so as not to obstruct the view of the other parts.

The end fitting of each tubing is indicated by the same reference character as the tubing. The valves 34-37 are held by a support 39 that is fastened to the front bar I6 by angles 40. The

angles are connected to the front bar l6 by screws 4|. 4

At the upper ends of the angles 40 there are bearings 42 for a valve actuator comprising a shaft 43 with cams 44-41 located above the valves 34-3l, respectively. Each of the cams 44-41 has a hub through which it is pinned to are so shaped and so related to each other that the cam-shaft 43 by a pin 49. The cams 44-41 they open the valve 34-31 in a predetermined sequence.

The cam "opens the pilot control valve 31 first to cause the pilot flame, which receives a small gas flow even when valve 31 is closed, to

increasein size for igniting gas that is to issue from the preheating jet oriflces of the tip. The cam 45 opens the valve 35 next and supplies fuel gas, preferably acetylene, to the preheating jet orifices of the torch. ,The cam then opens the valve 36 and permits oxygen to flow to the preheating flame jets. The opening of the acetylene valve 35 ahead of the oxygen valve 36 prevents flashbacks. v The acetylene is ignited by the, pilot flame beforethe oxygenvalve 36 opened. t i

The cam 44'opens the cutting oxygen valve 34 last, but the cams 45 and 46 are designed to hold the valves; 35' and .36 open while the cuttin oxygen valve is open. Since the pilot flame is not 'reachof an attendant who is standing near the torches or on the far side of the table I2 for guiding the tracer. t

Fig. 3 shows the valve36 with a valve rod- 5| extending upward under a lever 52 that has a bifurcated end connected by a pivot pin 53 to a lug on the valve. The valve rod 5| is held upward by spring bias that maintainsv the valve 36 normally closed, and the cam 46 presses the righthand endof the lever 52 downward to open the valve. The upstream side of the valve 36 is' connected by tubing 55 with .an oxygen supply line, Except for the shapeof the cams, the

structure of each of the valves 34-31 is similarshaft is in a position that causes all of the valves to, close, and thisnotch 6| has a steep side or shoulder that serves as a ratchet tooth .and provides a positive check for preventingmeverserotaticn of the cam shaft. This insures the proper starting sequence. .Other notches correspond to thepositions at which the valves-are open for preheating and for cutting. The notches 62 permit backward rotation from cutting to preheating positions. Y

The invention has been described as applied to a cutting machine, but it will be evident that a similar combination in a welding machine is a mechanical equivalent.

I claim:

1. A cutting machine including in combination a carriage with wheels at both sides for stably supporting the carriage, a. frame on the carriage for supporting a tracer and torch for universal movement in a plane with the tracer operating over a field between the paths followed by the wheels and the torch operating over a parallel field on the opposite side of one of said paths, valve means for controlling the supply of gas to the torch, and valve-actuator means extending transversely of the tracer field and including a handle accessible from the torch side of the tracer field, and another handle accessible from the other side of the tracer field.

2, Cutting apparatus includin pattern table, a wheeled carriage that runs onthe opposite edges of the table as guides, two Jointed arms with pivot connections by which the rearward ends of the arms are supported from thecarriage, means holding the corresponding links of the jointedarms parallelwith one another including a front bar pivotal ly connected with the forward ends of the links, a tracer connected with the bar in position to operate over the'pattern table, one or more torches located near one end of the bar beyond the pattem table, four valves on the front bar for controlling the supply of pilot flame gas, cutting oxygen, preheating-flame oxygen, and fuel gas for the one or more torches on the bar, a separate operating lever connected to each valve, bearings supported by the front bar, a

shaft rotatable in said bearings and extending acrossall four of the valves, four cams secured to the shaft, one in position to actuate each of the valves in accordance with a desired sequence, a disk secured to the shaft, a shoulder on the disk, a pawl cooperating with the shoulder, to prevent reverse rotation of the shaft, and a handle at extending lengthwise cf the bar and rotatable to actuate the valve means in sequence, handles at opposite ends of the shaft, one in the region of the tracer and the other in the region of the torch, and means associatedwith said shaft for preventing reverse rotation of the shaft so that an operator is required to turn the shaft toward the right when standing on one side of the machine and toward the left when standing on the other side. V

4. In a cutting machine, a plurality of valves for controlling the gas supply to a torch, including afuel gas control valve, a preheating-oxygencontrol valve, and a cutting-oxygen control valve, valve-operating means including a rotary cam shaft, a separate cam on the shaft for actuating each valve, the cams being constructed and arto hold the cam shaft in definite positions, and a ranged to open the valves in a'de'sired sequence and upon further rotation to cause the valves to close, and positive check means for preventing a reverse rotation of the cam shaft that would open the valves in a wrong sequence.

5. In cutting apparatus, a plurality of valves for controlling the supply of cutting oxygen, fuel gas, and preheating om'gen to one or more torches, separate cam means rotatable as a unit to cause said valves to open in a predetermined sequence and operable upon further rotation to cause said valves to close, and a positive check device for preventing reverse operation of the cam means. a

6. Cutting apparatus including separate valves for controlling the supply of gas to a cutting torch, said valves including one through which gas is supplied to a cutting jet, another that controls the gas supply to a pilot flame, one valve for controlling a supply of fuel gas for preheating flames and another valve through which oxygen is supplied to the preheating flames, a camshaft, four cams on said shaft, one in position to actuate each of the four valves, said cams being in such relation to each other that they cause the valves to open in a given sequence when the shaft is rotated in one direction, and to close direction, a disk on the shaft, notches in the disk corresponding to the open positions of the respective valves, a pawl that engages the notches when the shaft is rotated further in the same shoulder on the disk for positively preventin reverse rotation of the disk after it has rotated far enough to cause the valves to close after having been opened in said given sequence, and means urging the pawl against the disk.

'7. In a cutting machine, a plurality of valves for controlling the gas supply to a torch, including a preheating-oxygen control valve, and a cutting-oxygen control valve, valve-operating means including a cam shaft, cams on the shaft for operating the respective valves, said cams being constructed and arranged to operate the valves in a. certain sequence when rotated in one direction and to close the valves when rotated further. in the same direction, and a positive check device for preventing reverse rotation of the cam shaft after it has been rotated in said same direction far enough to close the valves.

8. In cutting apparatus, a plurality of valves .for controlling the supply of cutting oxygen, fuel gas, and preheating oxygen to one or more torches, rotary cam means that cause said valves to open in a predetermined sequence, and then close when the cam means are rotated in one direction, and a positive check devicefor preventing reverse operation of the cam means after they have been rotated far enough to cause the valves to close..

JAMES l). McKIERNAN. 

